Effects of morphology on phonons of nanoscopic silver grains
| dc.creator | Narvaez, Gustavo A. | |
| dc.creator | Kim, Jeongnim | |
| dc.creator | Wilkins, John W. | |
| dc.date | 2005-06-13 | |
| dc.date | 2005-10-15 | |
| dc.date.accessioned | 2026-07-07T06:37:57Z | |
| dc.date.available | 2026-07-07T06:37:57Z | |
| dc.description | The morphology of nanoscopic Ag grains significantly affects the phonons. Atomistic simulations show that realistic nanograin models display complex vibrational properties. (1) Single-crystalline grains. Nearly-pure torsional and radial phonons appear at low frequencies. For low-energy, faceted models, the breathing mode and acoustic gap (lowest frequency) are about 10% lower than predicted by elasticity theory (ET) for a continuum sphere of the same volume. The sharp edges and the atomic lattice split the ET-acoustic-gap quintet into a doublet and triplet. The surface protrusions associated with nearly spherical, high-energy models produce a smaller acoustic gap and a higher vibrational density of states (DOS) at frequencies ν<2 THz. (2) Twined icosahedra. In contrast to the single-crystal case, the inherent strain produce a larger acoustic gap, while the core atoms yield a DOS tail extending beyond the highest frequency of single-crystalline grains. (3) Mark's decahedra, in contrast to (1) and (2), do not have a breathing mode; although twined and strained, do not exhibit a high-frequency tail in the DOS. (4) Irregular nanograins. Grain boundaries and surface disorder yield non-degenerate phonon frequencies, and significantly smaller acoustic gap. Only these nanograins exhibit a low-frequency ν^2 DOS in the interval 1-2 THz. | |
| dc.description | Version published in Phys. Rev. B | |
| dc.identifier | https://arxiv.org/abs/cond-mat/0506299 | |
| dc.identifier | http://arxiv.org/abs/cond-mat/0506299 | |
| dc.identifier | Phys. Rev. B 72, 155411 (2005) | |
| dc.identifier | doi:10.1103/PhysRevB.72.155411 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/100572 | |
| dc.subject | Materials Science | |
| dc.title | Effects of morphology on phonons of nanoscopic silver grains | |
| dc.type | text |